If you own an Apple iPhone, iPad, or iPod touch and want to locate its UDID, then here is an easy way to do this task. First of all, you must know what UDID is:
UDID (Unique Device ID) or unique identifier number is a 40-digit sequence of letters and numbers, associated with every iPhone and iPod touch device.
To find iPhone/iPad/iPod touch UDID, follow the easy steps below:
1. Connect your device with the USB cable. Start iTunes on Windows or Mac.
2. Select your iPhone/iPod/iPad under the Devices menu, and open its Summary Tab.
3. You will see an entry named ‘Serial Number’ there, click on it.
4. Upon clicking, the word serial number will change to ‘Identifier (UDID)’.
5. A 40-digit UDID appears, which you can copy to the clipboard using the command (Ctrl + C on Windows) and (Command + C on Mac).